JPH0547924A - Semiconductor wafer - Google Patents

Abstract

PURPOSE:To reduce the warpage of a semiconductor wafer. CONSTITUTION:A thick oxide film 4' as insulator on a silicon wafer is formed in an island type. Stress inside an element can be disperesed outside scribe lines 5, and the warpage of a wafer as a cluster of elements can be prevented. Thereby troubles at the time of conveyance, damage of a wafer, and so forth can be reduced in a manufacturing line.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor wafer, and more particularly to a semiconductor chip in which a circuit is formed on a silicon substrate using an oxide film as an insulator.

[0002]

2. Description of the Related Art When manufacturing a semiconductor device, a semiconductor wafer 1 as shown in FIG. 3 is conventionally used, and various steps such as oxidation, impurity diffusion, photo-etching and wiring formation are performed on the semiconductor wafer 1. Are manufactured. The structure of the semiconductor chip on the semiconductor wafer 1 will be described with reference to FIG. FIG. 4 is an enlarged view of a part of FIG. In FIG. 4, 2 is a semiconductor chip, 3 is a thin oxide film in an area constituting a semiconductor circuit, 4 is a thick oxide film attached to enhance the insulating property of the chip, and 5 is for cutting the chip into individual pieces. It is a scribe line provided. However, no oxide film is attached here. The semiconductor device having the above-described structure is divided into individual pieces, mounted on a lead frame (not shown), connected with metal wires or the like, and covered with a mold to obtain a product.

[0003]

However, in the above conventional element structure, a thick oxide film is arranged in a loop shape on the outer peripheral portion of the pellet (especially in a power element having a high breakdown voltage). Such a structure has a drawback in that stress is generated in the pellet due to the difference in expansion coefficient between the silicon substrate and the oxide film, which causes warpage in the entire wafer.
In addition, the power element in which a current flows vertically through the pellet is disadvantageous for warping of the wafer because the thickness of the wafer is made as thin as possible in order to reduce the resistance.

[0004]

Therefore, the present invention is characterized in that a thick oxide film is formed in an island shape in a semiconductor chip that constitutes a circuit using an oxide film as an insulator on a silicon substrate.

[0005]

According to the above construction, the stress inside the pellet can be released to the scribe line of the semiconductor chip, so that the warp of the entire wafer can be prevented. Further, as a result of this, the wafer thickness can be made thinner than the current one, so that improvement in characteristics can be expected.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a plan view of an embodiment of the present invention. 1 is an enlarged view of a part of a wafer similar to FIG. 3, in which 2 is a semiconductor chip (element), 3 is a thin oxide film, 4'is a thick oxide film, and 5 is a scribe line.

In FIG. 1, the thin oxide film 3 and the thick oxide film 4'are arranged in an island shape. Thin oxide film 3
In the area marked with, a window (called a bonding pad, not shown here) for making contact with the circuit of the semiconductor element or an external electrode is formed. The thick oxide film 4'is provided to enhance the insulating property, and a high voltage circuit or the like is provided in the vicinity thereof. According to this embodiment, even if there is a difference in expansion coefficient between the underlying silicon and the oxide films 3 and 4 ′,
Since the oxide film is divided into islands by the scribe lines 5, there is an advantage that stress is dispersed in the chip 2. With such a configuration, the stress applied to the entire wafer can be reduced, and the warp of the wafer can be prevented. Further, as compared with the conventional case, the area that can be used as a circuit (the portion 3 where a thin oxide film is attached) is expanded, so that there is an advantage that the stacking degree can be improved.

[0008]

Second Embodiment FIG. 2 is a plan view of a second embodiment of the present invention. In this embodiment, the thick oxide film 4'of the first embodiment is used.
Since the second embodiment is the same as the first embodiment except that the way of attaching is changed, the same portions are denoted by the same reference numerals and the description thereof will be omitted.

In this embodiment, a plurality of thick oxide films 4 "are arranged so as to overlap a part of the frame-like C-shape, and when it is desired to enhance the insulating property as compared with the first embodiment. Such a structure has an advantage that the stress inside the pellet can be reduced without impairing the insulating property.

[0010]

As described above, according to the present invention, by arranging the thick oxide film formed on the silicon substrate in an island shape, the stress generated inside the pellets is dispersed and reduced, so that the warpage of the entire wafer is prevented. There is an effect that can be prevented.

[Brief description of drawings]

FIG. 1 is a plan view of a first embodiment of the present invention.

FIG. 2 is a plan view of a second embodiment of the present invention.

FIG. 3 is a substrate of silicon which is a material for manufacturing a semiconductor device.

FIG. 4 is a plan view showing a conventional example.

[Explanation of symbols]

 1 semiconductor wafer 2 semiconductor chip 3 thin oxide film 4 ', 4 "thick oxide film 5 scribe line

Claims (2)

[Claims] 1. A semiconductor wafer, wherein a thick oxide film is formed in an island shape in a semiconductor chip that constitutes a circuit using an oxide film as an insulator on a silicon substrate. 2. A semiconductor wafer, characterized in that a thick oxide film is formed in a frame-like island shape with a part missing.